Surface-active agents and oil compositions containing them



United States Patent SURFACE-ACTIVE AGENTS AND OIL COMPOSI- TIONSCONTAINING THEM Richard D. Stayner and Robert A. Stayner, Berkeley,

No Drawing. Application December 22, 1951, Serial No. 262,996

Claims. (Cl. 52--0.5)

This invention relates to new and useful oil-soluble surface-activeagents and compositions containing them. More particularly, thisinvention relates to oil-soluble surface-active agents of an ionicnature which contain both an ionic carboxyl group and a cationicquaternary ammonium group within the same molecule and to improvedhydrocarbon oil compositions containing them.

In accordance with the present invention, it has been discovered thatnew and useful oil-soluble ampholytic surface-active agents having bothcationic and anionic characteristics may be prepared by reacting adi-(alkylarylrnethylene)-alkanolamine, a di-(alkylarylmethylene)-alkylamine, an alkylarylmethylene dialkanolamine or analkylarylmethylene dialkylamine with an alkali metal or alkaline earthsalt or an alkyl ester of a monohalogenated aliphatic carboxylic acid.The novel products thus obtained may be illustrated by the followingstructural formula:

wherein at least one but not more than two of the groups R1, R2 and R3are long-chain alkylarylmethylene groups having from 9 to 18 carbonatoms in each long-chain alkyl substituent, the remainder being membersof the class consisting of short-chain alkyl and hydroxyalkyl groupscontaining from 1 to 7 carbon atoms and R4 is an alkylene group of from1 to 7 carbon atoms.

The above compounds are generally useful as surfaceactive agents. Theyare oil-soluble and are useful in hydrocarbon oil compositions such aslubricating oils and fuel oils as dispersing agents and rust inhibitors.their unusual amphoIytic or ,amphoteric nature, these compounds combinesome of the beneficial aspects of both r cationic and anionicsurface-active agents.

According to the invention, the compounds as illustrated in the abovestructural formula contain at least one alkylaryl group, each of whichis connected by a methylene linkage to the nitrogen. Examples ofsuitable aryl groups include benzene, naphthalene, anthracene, toluene,xylene, mesitylene, etc. with benzene and toluene being preferred fortheir availability and the high degree of effectiveness characteristicof the compounds containing them. The alkyl substituents on the arylnucleus may be straight-chain or branched-chain in, nature and may varyfrom 9 to 18 carbon atoms in length. For present purposes propylenepolymers containing from 9 to 18, and more specifically from 12 to 15,carbon atoms per mole cule are preferred because of their readyavailability and their chemical stability derived, apparently, from thecharacteristically moderate chain-branching of the propylene polymers ingeneral.

In the above structural formula illustrating the invention, the N-alkylor N-hydroxyalkyl portion may be'con- Due to veniently derived from anyprimary alkyl or hydroxy.

.89 amine, butanolam ne, d meth ylarmne hydrochloride, d1-

2,697,656 Patented Dec. 21, 1954 ice isopropylamine hydrochloride, etc.Methylamine, dimethylamine, dimethylamine hydrochloride, ethylamine,ethanolamine and di-ethanolamine are presently preferred.

The nature of the alkylene group R4 in the structural formula isdetermined by the particular monohalogenated aliphatic carboxylic acidsalt or ester employed in the preparation of the compounds according tothe invention. Suitable halogenated acid salts or esters include sodiummonochloroacetate, potassium monobromopropionate, sodium a-bromon-butyrate, potassium a-bromo valerate, calcium iodoacetate, magnesiumchloroacetate, methyl monochloroacetate, isopropyl monobromo-n-butyrate,etc. For their effectiveness and ready availability sodiummonochloroacetate and methyl chloroacetate are presently preferred.

The N,N-di-(alkylbenzyl) and N-alkylbenzyl glycines constituting thepreferred embodiment of the invention may be illustrated by the formula:

wherein R is a long-chain alkyl group of from 9 to 18 carbon atoms, R isa member of the group consisting of hydrogen and methyl, x is an integerof from 1 to 3 and R" is a member selected from the class consisting ofmethyl, ethyl and hydroxyethyl groups.

An important advantage of the present invention lies in the processwhereby the above preferred group of compounds may be prepared. Suitablealkylbenzenes, alkyltoluenes, or alkylxylenes such as nonylbenzene,dodecylbenzene, dodecyltoluene, etc. may be chloromethylated by suitablemeans, as, for example, by reacting them with formaldehyde orpara-formaldehyde and hydrogen chloride in the presence of a catalystsuch as an anhydrous mixture of zinc chloride and acetic acid. Theresulting alkylbenzyl chloride is a very stable and highly reactiveintermediate which may be condensed with any of the aforementionedprimary and secondary amines to produce the N,N di-(alkylbenzyl)- andN-alkylbenzyl tertiary amines used in the preparation of the compoundsof this invention. It reacts much more cleanly with the primary andsecondary amines than would the corresponding long-chain alkyl halidesand the N,N-di-(alkylbenzyl)-.' and N-alkylbenzyl glycines derived fromthe resulting tertiary amines are remarkably free of undesirableby-products of side reactions.

The condensation of the alkylbenzyl chloride with the primary orsecondary amine or amine salt to form the corresponding tertiary aminesas referred to above may be carried out according to any suitable methodknown .to the art. For present purposes it is preferred that thealkylbenzyl chloride and amine be condensed with the aid of a mildneutralization agent, such as sodium bicarbonate, while warming thereaction mixture slightly, usually in the temperature range of from to200 F.

The N,N-di-(alkylbenzyl)-N-alkanolor alkyl tertiary amines orN-alkylbenzyl-N,N-dialkanolor dialkyl tertiary amines resulting from theforegoing preparations may then be reacted with a suitable salt or esterof a monohalogenated aliphatic carboxylic acid of the type describedabove, such as, sodium monochloroacetate .or methyl chloroacetate, toform the oil-soluble ampholytic surface-active agents of this invention.If desired, the

reaction may be carried out in the presence of an inorganic iodide, suchas potassium iodide, which acts as a promoter and the mixture may bewarmed sli htly to a temperature in the ran e of from 100 to 200 F.

For convenience of handling, solvents for the above reaction mixturesmay be employed. Suitable solvents Example I.Preparation ofN,N-di-(dodecylbenzyl)- ethanolamine 140 parts of dodecylbenzyl chloridewas added dropwise to a mixture of 15% parts of ethanolamine and 42parts of sodium bicarbonate in an isopropanol-water solution. Theaddition was carried out over a period of one hour at a temperature offrom 120 to 125 F. Following the addition, the stirred mixture wasrefluxed for two hours, filtered to remove inorganic salts and thendiluted with mixed hexanes. The diluted solution was next washed withwater, dried over anhydrous calcium sulfate and concentrated underreduced pressure to give 143 parts ofN,N-di-(dodecylbenzyl)-ethanolamine in the form of yellow oil.

Example 2.Preparation of N,N-di-(ddecylbenzyl)- N-Z-hydroxyethyl glycineAn isopropanol solution of 52 parts ofN,N-di-(dodecylbenzyl)-ethanolamine prepared in Example 1 was refluxedwith 13 parts of sodium chloroacetate and 3 parts of potassium iodidefor 12 hours. The mixture was then filtered to remove inorganic saltsand the solution washed with water and extracted with mixed hexanes. Themixed hexane solution was then evaporated under reduced pressure to givethe N,N-di-(dodecylbenzyl)-N-2- hydroxyethyl glycine in the form of aviscous, yellow liquid.

Example 3.Preparation of N-nonylbenzyl-dz'ethanolamine The alcoholicportion was alkalized to pH 10.0 with per cent sodium hydroxide solutionand the product extracted with 200 parts of mixed hexanes. The hexanesolution was then washed with water and concentrated under reducedpressure to give 46 parts of N-nonylbenzyldiethanolamine as a viscous,yellow liquid. Analysis: per cent N (calc.)=4.37; per cent N(found)=4.11.

Example 4.--Preparati0n of N-nonylbenzyl-N,N-di-(2- hydroxyethyl)-glycz'ne A mixture of 41 parts of N-nonylbenzyl-diethanolamine(prepared in Example 3), 23 parts of methyl chloroacetate, 5 parts ofpotassium iodide and 100 parts of ethyl alcohol was stirred and refluxedfor hours. A solution of 16 parts of sodium bicarbonate in 150 parts ofwater was added portionwise and the mixture was again refluxed for 3hours. The pH was adjusted to 9.5 with caustic and the solution wasrefluxed two hours, cooled, diluted with 200 parts of methanol'and thenextracted with mixed hexanes. The alcoholic portion was washed withwater and the product concentrated under reduced pressure to give 24parts of N-nonylbenzyl-N,N- di-(Lhydroxyethyl)-glycine as ayellow-colored, viscous liouid. Analvsis: per cent N (calc.)=3.70; percent N (found)=3.68.

Example 5.Preparation of N-dodecylbenzyl-N,N- dimethylamine ture wasrefluxed two hours, filtered and acidified to pH 2.0 w th concentratedhydrochloric acid. The solution was extracted with two part portions ofmixed hexanes and then alkalized to pH 8.5 with caustic solution. Theproduct was taken up in mixed hexanes, washed with water, concentratedby evaporation of most of the solvent and then distilled collecting thefraction boiling at 266 to 293 F. at 2 mm. There was obtained 34 partsof N-dodecy1benzyl-N,N-dimethylamine as a colorless liquid.

Example 6.Preparati0n 0f N-dodecylbenzyl-N,N- dimethylglycine A stirredmixture of 4.7 parts of chloroacetic acid, 2.8 parts of potassiumhydroxide and 100 parts of ethanol was warmed slowly to F. until thesolution became clear, and then 3.1 parts of potassium iodide and 12.5parts of N-dodecylbenzyl-N,N-dimethylamine (prepared in Example 5) wereadded. The mixture was stirred and refluxed for six hours, filtered andmade alkaline with caustic. The alcoholic solution was washed first withtwo 100-part portions of mixed hexanes and then with two 100-partportions of water. The product was dissolved in 50 parts of benzene andthen concentrated under reduced pressure to give 12 parts ofN-dodecylbenzyl- N,N-dirnethylglycine as a colorless grease. Analysis:per cent N (ca1c.)=3.75; (found)=3.50.

The proportions given in the foregoing examples are on a weight basisunless otherwise specified.

' As mentioned above, the present invention is also concerned with thepreparation of improved hydrocarbon fuels and, more particularly, withhydrocarbon fuels having improved properties as burner, diesel and jetfuels.

In the production of burner fuels, diesel and jet fuels, it isdesirable, economically, to employ considerable quantities of crackedrefinery stocks. Such stocks are becoming more and more available due tothe everincreasing use of thermal and catalytic cracking processes inpetroleum refinery operations. When employed in burner fuels and dieseland jet fuels, these stocks have the disadvantage of forming particlesof sludge or gum which tend to deposit and cause plugging of filters,screens and lines. The necessity for frequent interruptions of burnerand diesel engine service to replace or unplug clogged filters andscreens constitutes a serious problem.

Burner, diesel and jet fuel systems ordinarily contain certain amountsof water due to vapor condensation. The presence of this water tends toaccelerate the formation of filter plugging gum and sludge in suchfuels, particularly those containing cracking stocks, and also causerusting of exposed ferrous metal surfaces which ust in turn eventuallyloosens and clogs the filters and mes.

As part of the present inventionit has been discovered that by theaddition of a small amount of an oil-soluble ampholytic surface-activeagent of the type described above to normally liquid hydrocarbon fuels,anv tendency of the fuel to form filter clogging particles of sludge orgum is substantially overcome. Such hydrocarbon fuel compositions, inaddition, have the effect of inhibiting rusting of ferrous metalsurfaces with which they come in contact, thus substantially eliminatingrust particles that may also lead to clogging of fuel oil systems.

The hydrocarbon fuel base stocks suitable for use in the improved fueloil compositions of the present invention may be described broadly aspetroleum distillates b i ing in the ran e of from about 350 F. to about750 F. Such distillates are ordinarily characterized by an APT ravity ofat least 20 degrees and usuallv at least 25 de rees. The base stocks maybe either straightrun distillates or cracked distillates. The presentinvention finds its greatest utility in hydrocarbon fuels of thepreceding tvoes which contain substantial amounts of crackeddistillates. Without the additives of this invention, such fuels form apreciable amounts of filter plugging sludge and gum which render themunsuitable for use in operations where interrupted service is desired,as is the case with most present-day operations.

Very small amounts of the additives, in the order of 1% by weight orless, have been found to be entirely effective for a prevention of lineand filter clogging and also the inhibition of rusting when Water ispresent in the system. Amounts in the range of from 0.001 to 0.20% byweight of the total fuel are particularly suitable and proportions inthe range of from 0.005 to 0.015% by weight are most preferred in themore specific embodiments of the invention.

s .-In order to facilitate'evaluation of the improved fuel oilcompositions of the present'invention and avoid an enormous outlay oftime and material, a rapid test method for determining filter pluggingcharacteristics was developed. The results of this test method have beenfound to correlate well with actual field tests, using regular fuel oilburners and diesel and jet engines. The test is carried out by mixing500 milliliters of a fuel composition containing 0.01% by weight ofadditive with 500 milliliters of water containing 102 parts per millionhardness calculated as calcium and magnesium carbonates, two-thirdsbeing calcium carbonate. The fuel oil composition and water are shakenin a separatory funnel for 30 seconds, at the end of which they areallowed to. stand for minutes. At this point a phase separation occursand an upper oil layer and a-lower water layer are obtained, usuallyseparated by an opaque cutf attheir interface. This interface cuff isthen filtered through a fritted glass crucible with the aid of a vacuum.Only as much oil and water are filtered as are necessary to assurecomplete extraction of the cuff, usually about milliliters. However, incases of severe emulsions the entire content of the separatory funnelmay have to be filtered. The resultant discoloration of the crucible matby the particles of gum and sludge deposited is used as a comparativemeasure of the hydrocarbon fuels tendency to plug filters and screens.

In the comparison, the filter is compared with a standard series of 11filters prepared in a similar manner from fuels of known filter-pluggingtendency. The standard filters are numbered 0 to 10, the higher numbersbeing identified with the higher deposits. For convenience, the ratinggiven a particular test sample is termed its Interface Filter DepositRating (IFD) and denotes the number of the filter in the standard serieswith which it compares in amount of filter deposit.

Table I, which follows, shows the IFD values of a number of fuel oilcompositions according to the present invention as compared with astandard diesel, burner or jet fuel. The base fuel employed in each casewas a mixture of equal parts of straight run distillate from a waxy basecrude boiling in the range of from 384 F. to 675 F. and a Thermoforcatalytic cracked fraction boiling in the range of from 376 F. to 566 F.

The data in Table I above clearly shows the marked superiority of theimproved hydrocarbon fuel compositions according to the presentinvention over a conventional diesel, jet or burner fuel. Run 1 showsthat no filter deposit is obtained from fuel oil compositions containinga representative agent, whereas the fuel oil base stock itself gives anextremely high filter deposit.

The fuel oil compositions of the present invention were also tested fortheir rust-inhibiting properties. The tests were carried out inaccordance with the procedure outlined in ASTM method D665-47T. Steelspindles were immerged in an agitated distilled water and fuel oilmixture containing 0.001% by weight of additive and in an agitated seawater and fuel oil mixture containing 0.005% by weight of additive. Thebase stock fuel was tested in a similar fashion. The results of thesetests are as From the above tests it will be readily observed that theimproved fuel oil compositions of this invention p'ossess remarkablerust-inhibiting properties as compared to ordinary diesel, jet or burnerfuels.

The fuel oil compositions according to the present invention may alsocontain other fuel oil additives in addition to the oil-solubleampholytic surface-active agents of this invention. Such additivesinclude: lecithin; oil-soluble alkylaryl polyglycol ethers such asdidodecylphenyl-dodecaethylene glycol ether; oil-soluble sulfonates suchas the lead salts of petroleum sulfonic acids containing from about 20to 30 carbon atoms per molecule; oil-soluble naphthenates such as thealkali metal and lead salts of petroleum naphthenic acids; alaali metaland lead salts of alkylphenyl disulfides.

We claim:

1. Oil-soluble surface active compounds having the formula:

wherein at least one but not more than two of the groups R1, R and R arelong-chain alkylbenzyl groups having a long-chain alkyl substituent oneach benzene nucleus containing from 9 to 18 carbon atoms, the remainderbeing members of the class consisting of short-chain alkyl andhydroxyalkyl groups containing from 1 to 7 carbon atoms.

2. Oil-soluble surface active N,N-di-(alkylbenzyl)-N- alkanol glycineshaving a long-chain alkyl substituent on each benzene nucleus containingfrom 9 to 18 carbon atoms and an alkanol substituent on the nitrogencontaining from 1 to 7 carbon atoms.

3. Oil-soluble surface active N,N-di-(alkylbenzyl)-N- alkyl glycineshaving a long-chain alkyl substituent on each benzene nucleus containingfrom 9 to 18 carbon atoms and an alkyl substituent on the nitrogencontaining from 1 to 7 carbon atoms.

4. Oil-soluble surface active N-alkylbenzyl-N,N-dialkanol glycineshaving a long-chain alkyl substituent on the benzene nucleus containingfrom 9 to 18 carbon atoms and alkanol substituents on the nitrogencontaining from 1 to 7 carbon atoms each.

5. N,N-di-(dodecylbenzyl)-N-methyl glycine.

6. N-dodecylbenzyl-N,N-di-Z-hydroxyethyl glycine.

7. N,N-di-(dodecylbenzyl)-N-2-hydroxyethyl glycine.

8. A process which comprises heating at a temperature between about and200 F. 2 molar proportions of an alkylbenzyl chloride having from 9 to18 carbon atoms in the alkyl portion thereof with 1 molar proportion ofethanolamine in the presence of sodium bicarbonate, heating at atemperature between about 100 and 200 F. theN,N-di-(alkylbenzyl)-ethanolamine thus obtained with sodiummonochloroacetate in the presence of potassium iodide to give anoil-soluble, surface-active N,N-di-(alkylbenzyl)-N-2-hydroxyethylglycine having a long-chain alkyl substituent on each benzene nucleuscontaining from 9 to 18 carbon atoms.

9. A hydrocarbon oil composition containing a small amount suflicient toinhibit line and filter clogging and corrosion of a compound having thefollowing formula:

wherein at least one but not more than two of the groups R1, R2 and R3are long-chain alkylbenzyl groups having a long-chain alkyl substituenton each benzene nucleus containing from 9 to 18 carbon atoms, theremainder being members of the class consisting of short-chain alkyl andhydroxyalkyl groups containing from 1 to 7 carbon atoms.

10. A hydrocarbon fuel oil composition comprising a major proportion ofa normally liquid hydrocarbon fuel oil and a small amount sufiicient toinhibit line and filter clogging and corrosion of anN,N-di-(alkylbenzyl)-N- alkanol glycine having a long-chain alkylsubstituent on each benzene nucleus containing from 9 to 18 carbon atomsand an alkanol substituent on the nitrogen containing from 1 to 7 carbonatoms.

11. A hydrocarbon fuel oil composition comprising a major proportion ofa normally liquid hydrocarbon fuel oil and a small amount sufficient toinhibit line and filter clogging and corrosion of an N-alkylbenzyl-N,N-dialka- 1101 glycine having a long-chain alkyl substituent on thebenzene containing from 9 to 18 carbon atoms and alkanol substituents onthe nitrogen containing from 1 to 7 carbon atoms each.

12. A hydrocarbon fuel oil composition comprising a major proportion ofa normally liquid hydrocarbon fuel oil and a small amount sufiicient toinhibit line and filter clogging and corrosion of anN,N-di-(alky1benzyl)- N-alkyl glycine having a long-chain alkylsubstituent on each benzene nucleus and containing from 9 to 18 carbonatoms and an alkyl substituent on the nitrogen containing from 1 to 7carbon atoms.

13. A hydrocarbon fuel oil composition comprising a major proportion ofa normally liquid hydrocarbon fuel oil boiling in the range of fromabout 350 F. to about 750 F. and a small amount not exceeding 1% byweight of N,N-di-(dodecylbenzyl)-N-methyl glycine, said fuel oilcontaining a substantial proportion of cracked petroleum distillate.

14. A hydrocarbon fuel oil composition comprising a major proportion ofa normally liquid hydrocarbon fuel oil boiling in the range of fromabout 350 F. to about 750 F. and a small amount not exceeding 1% byweight of N,N di (dodecylbenzyl)-N-2-hydroxyethyl glycine,

' 8 said 'fuel oil containing a substantial proportion of crackedpetroleum distillate.

15. A hydrocarbon fuel oil composition comprising a major proportion ofa normally liquid hydrocarbon fuel oil boiling in the range of fromabout 350 F. to about 750 F. and a small amount not exceeding 1% byweight of N-dodecylbenzyl-N,N-di-Z-hydroxyethyl glycine, said fuel oilcontaining a substantial proportion of cracked petroleum distillate.

1. OIL-SOLUBLE SURFACE ACTIVE COMPOUNDS HAVING THE FORMULA: